Sandstone hills that have been tipped down along a fault. On the other side of this ridge is the Morrison formation. This is formation where the Jurassic dinosaurs have been found and quarried. A building has been built over the quarry site and it was a very popular visiting place. People came from all over the world to see the dinosaur quarry. The National Park Service has decided that the building is not safe so visitor are not allowed to see the quarry. Do they do the repairs and allow people to see what the quarry? No.....So visitors each year have declined until this Park is way down in visitation. The Monument controls many square miles that have nothing to do with dinosaurs but access is very limited. That is unless you get the necessary permits and walk. If I sound like I believe the National Parks and Monuments are not doing a very good job.....you are right.